Menguji ViewPager (dan CursorLoader) dengan Robolectric

Adakah yang tahu cara menguji penyiapan berikut menggunakan Robolectric?

Fragmen berisi ViewPager, data dimuat dengan CursorLoader.

Dengan kode di bawah ini, CursorLoader tidak pernah didorong ke adaptor untuk halaman tampilan. Saya terjebak di await()telepon.

EventsFragmentTest.java:

@RunWith(CustomRobolectricTestRunner.class)
public class EventsFragmentTest extends AbstractDbAndUiDriver
{
    // which element in the view pager we are testing
    private static final int           TEST_INDEX = 0;

    protected SherlockFragmentActivity mActivity;
    protected EventsFragment_          mFragment;

    @Override
    @Before
    public void setUp() throws Exception
    {
        // create activity to hold the fragment
        this.mActivity = CustomRobolectricTestRunner.getActivity();

        // create and start the fragment
        this.mFragment = new EventsFragment_();
    }

    @Test
    public void sanityTest()
    {
        // create an event
        final Event event = this.createEvent();

        // create mock cursor loader
        final Cursor cursor = this.createMockEventCursor(event);
        this.mFragment.setCursorLoader(mock(CursorLoader.class));
        when(this.mFragment.getCursorLoader().loadInBackground()).thenReturn(cursor);
        CustomRobolectricTestRunner.startFragment(this.mActivity, this.mFragment);

        await().atMost(5, SECONDS).until(this.isCursorLoaderLoaded(), equalTo(true));

        // check for data displayed
        final TextView title = this.getTextView(R.id.event_view_title);
        final TextView text = this.getTextView(R.id.event_view_text);

        // exists and visible is enough for now
        this.getImageView(R.id.event_view_image);

        assertThat(title.getText().toString(), equalTo(event.getTitle()));
        assertThat(text.getText().toString(), is(event.getText()));

        // clean up
        cursor.close();
    }

    @Override
    protected View getRootView()
    {
        return ((ViewPager) this.mFragment.getView().findViewById(R.id.events_pager)).getChildAt(TEST_INDEX);
    }

    private Callable<Boolean> isCursorLoaderLoaded()
    {
        return new Callable<Boolean>()
        {
            public Boolean call() throws Exception
            {
                return EventsFragmentTest.this.mFragment.isCursorLoaderLoaded(); // The condition that must be fulfilled
            }
        };
    }

    /**
     * Create an event
     * 
     * @return
     */
    protected Event createEvent()
    {
        // create a random event
        final Event event = new Event();
        event.setImage(null);
        event.setLink("/some/link/" + RandomUtils.getRandomString(5)); //$NON-NLS-1$
        event.setResourceUri("/rest/uri/" + RandomUtils.getRandomDouble()); //$NON-NLS-1$
        event.setText("this is a test object " + RandomUtils.getRandomString(5)); //$NON-NLS-1$
        return event;
    }

    protected Cursor createMockEventCursor(final Event event)
    {
        // Create a mock cursor.
        final Cursor cursor = new CursorWrapper(mock(MockCursor.class));

        when(cursor.getCount()).thenReturn(1);
        when(cursor.getString(cursor.getColumnIndexOrThrow(EventTable.COLUMN_TEXT))).thenReturn(event.getText());
        when(cursor.getString(cursor.getColumnIndexOrThrow(EventTable.COLUMN_TITLE))).thenReturn(event.getTitle());
        when(cursor.getString(cursor.getColumnIndexOrThrow(EventTable.COLUMN_IMAGE))).thenReturn(event.getImage());
        when(cursor.getString(cursor.getColumnIndexOrThrow(EventTable.COLUMN_LINK))).thenReturn(event.getLink());
        when(cursor.getString(cursor.getColumnIndexOrThrow(EventTable.COLUMN_RESOURCE_URI))).thenReturn(
                        event.getResourceUri());

        // return created event
        return cursor;
    }

}

EventsFragment.java

@EFragment(resName = "events_fragment")
public class EventsFragment extends SherlockFragment implements LoaderCallbacks<Cursor>
{
    @ViewById(R.id.events_pager)
    protected ViewPager             mPager;

    @ViewById(R.id.events_indicator)
    protected CirclePageIndicator   mIndicator;

    @Pref
    protected ISharedPrefs_         mPreferences;

    protected EventsFragmentAdapter pageAdapter;

    private CursorLoader            mCursorLoader;

    /**
     * initialise the cursoradapter and the cursor loader manager.
     */
    @AfterViews
    void init()
    {
        final SherlockFragmentActivity activity = this.getSherlockActivity();

        this.pageAdapter = new EventsFragmentAdapter(activity.getSupportFragmentManager(), null);
        this.mPager.setAdapter(this.pageAdapter);
        this.mIndicator.setViewPager(this.mPager);
        this.getLoaderManager().initLoader(this.mPager.getId(), null, this);
    }

    /* (non-Javadoc)
     * @see android.support.v4.app.LoaderManager.LoaderCallbacks#onCreateLoader(int, android.os.Bundle)
     */
    @Override
    public Loader<Cursor> onCreateLoader(final int arg0, final Bundle arg1)
    {
        if (this.mCursorLoader == null)
        {
            // set sort to newest first
            final String sortOrder = BaseColumns._ID + " DESC"; //$NON-NLS-1$

            this.mCursorLoader = new CursorLoader(this.getActivity(), EventContentProvider.CONTENT_URI,
                            EventTable.getProjection(), AbstractDbTable.getWhereCondition(null),
                            AbstractDbTable.getWhereArgs(this.mPreferences, null), sortOrder);
        }
        return this.mCursorLoader;
    }

    /* (non-Javadoc)
     * @see android.support.v4.app.LoaderManager.LoaderCallbacks#onLoadFinished(android.support.v4.content.Loader, java.lang.Object)
     */
    @Override
    public void onLoadFinished(final Loader<Cursor> arg0, final Cursor cursor)
    {
        this.pageAdapter.swapCursor(cursor);

    }

    /* (non-Javadoc)
     * @see android.support.v4.app.LoaderManager.LoaderCallbacks#onLoaderReset(android.support.v4.content.Loader)
     */
    @Override
    public void onLoaderReset(final Loader<Cursor> arg0)
    {
        this.pageAdapter.swapCursor(null);
    }

    /**
     * Required for testing only.
     * 
     * @param cursorLoader
     */
    public void setCursorLoader(final CursorLoader cursorLoader)
    {
        this.mCursorLoader = cursorLoader;
    }

    /**
     * Required for testing only.
     * 
     * @param cursorLoader
     */
    public CursorLoader getCursorLoader()
    {
        return this.mCursorLoader;
    }

    public boolean isCursorLoaderLoaded()
    {
        return (this.pageAdapter.getCursor() != null);
    }
}

Saya tidak yakin, tapi saya berani bertaruh bahwa kode internal mencoba menggunakan AsyncTaskuntuk memanggil metode cursor loader loadInBackground(). Anda mungkin melihat kebuntuan karena AsyncTaskupaya untuk memanggil onPostExecute(). Panggilan tersebut akan mencoba dijalankan di thread UI utama Anda, yang kebetulan merupakan thread rutin pengujian Anda. Itu tidak akan pernah terjadi karena Anda terjebak dalam menunggu dengan rutinitas pengujian Anda di tumpukan panggilan.

Coba pindahkan mocking Anda ke level yang lebih tinggi sehingga tidak ada yang benar-benar terjadi di latar belakang dari pengujian. google ʻAsyncTask unit test android deadlock ' untuk melihat contoh di mana orang lain mengalami masalah serupa.